As much I’d like to reward a server for a job well done, there are many times (in fact most of the time) when I literally cannot afford it.

I’m currently an unemployed student, so whatever money I have is from student loans or money my parents gave me. If I eat out, it usually is a very special…

Said so much more politely than I could have put it.  If you cannot afford to tip, you cannot afford to eat at that restaurant.  Period.